Covalency magnetic axiality in Nd molecular magnets: Nd-photoluminescence, strong ligand-field, and unprecedented nephelauxetic effect in fullerenes NdMN@C (M = Sc, Lu, Y).

Nd-based nitride clusterfullerenes NdMN@C with rare-earth metals of different sizes (M = Sc, Y, Lu) were synthesized to elucidate the influence of the cluster composition, shape and internal strain on the structural and magnetic properties. Single crystal X-ray diffraction revealed a very short Nd-N bond length in NdScN@C. For Lu and Y analogs, the further shortening of the Nd-N bond and pyramidalization of the NdMN cluster are predicted by DFT calculations as a result of the increased cluster size and a strain caused by the limited size of the fullerene cage.

Metallofullerene photoswitches driven by photoinduced fullerene-to-metal electron transfer.

We report on the discovery and detailed exploration of the unconventional photo-switching mechanism in metallofullerenes, in which the energy of the photon absorbed by the carbon cage π-system is transformed to mechanical motion of the endohedral cluster accompanied by accumulation of spin density on the metal atoms. Comprehensive photophysical and electron paramagnetic resonance (EPR) studies augmented by theoretical modelling are performed to address the phenomenon of the light-induced photo-switching and triplet state spin dynamics in a series of Y Sc N@C ( = 0-3) nitride clusterfullerenes. Variable temperature and time-resolved photoluminescence studies revealed a strong dependence of their photophysical properties on the number of Sc atoms in the cluster.

Air-stable redox-active nanomagnets with lanthanide spins radical-bridged by a metal-metal bond.

Engineering intramolecular exchange interactions between magnetic metal atoms is a ubiquitous strategy for designing molecular magnets. For lanthanides, the localized nature of 4f electrons usually results in weak exchange coupling. Mediating magnetic interactions between lanthanide ions via radical bridges is a fruitful strategy towards stronger coupling.

Thermally Activated Delayed Fluorescence in a Y N@C Endohedral Fullerene: Time-Resolved Luminescence and EPR Studies.

The endohedral fullerene Y N@C exhibits luminescence with reasonable quantum yield and extraordinary long lifetime. By variable-temperature steady-state and time-resolved luminescence spectroscopy, it is demonstrated that above 60 K the Y N@C exhibits thermally activated delayed fluorescence with maximum emission at 120 K and a negligible prompt fluorescence. Below 60 K, a phosphorescence with a lifetime of 192±1 ms is observed.

Confining the spin between two metal atoms within the carbon cage: redox-active metal-metal bonds in dimetallofullerenes and their stable cation radicals.

Lanthanide-lanthanide bonds are exceptionally rare, and dimetallofullerenes provide a unique possibility to stabilize and study these unusual bonding patterns. The presence of metal-metal bonds and consequences thereof for the electronic properties of M@C (M = Sc, Er, Lu) are addressed by electrochemistry, electron paramagnetic resonance, SQUID magnetometry and other spectroscopic techniques. A simplified non-chromatographic separation procedure is developed for the isolation of Er@C (C(6) and C(8) cage isomers) and Sc@C (C(8) isomer) from fullerene mixtures.

In situ Raman cell for high pressure and temperature studies of metal and complex hydrides.

A novel cell for in situ Raman studies at hydrogen pressures up to 200 bar and at temperatures as high as 400 °C is presented. This device permits in situ monitoring of the formation and decomposition of chemical structures under high pressure via Raman scattering. The performance of the cell under extreme conditions is stable as the design of this device compensates much of the thermal expansion during heating which avoids defocusing of the laser beam.

Charged states of α,ω-dicyano β,β'-dibutylquaterthiophene as studied by in situ ESR UV-vis NIR spectroelectrochemistry.

The influence of the molecular structure on the stabilization of charged states was studied in detail by in situ ESR UV-vis NIR spectroelectrochemistry at a novel α,ω-dicyano substituted β,β'-dibutylquaterthiophene (DCNDBQT) and the electrochemically generated cation and anion radicals have been proved for the first time. The voltammetry of DCNDBQT results in two separate oxidation steps with the reversible first one. The experimental absorption maxima at 646 and 1052 nm together with the calculated ones (by DFT method) as well as an ESR signal at the first anodic step prove the presence of a radical cation.

In situ NMR spectroelectrochemistry of higher sensitivity by large scale electrodes.

The combination of NMR spectroscopy and electrochemistry provides an in situ method to measure structural changes of the redox components in an electrochemical reaction by proton NMR experiments. As the use of metal thin film radio frequency (RF) transparent electrodes in NMR spectroelectrochemical studies is limited by layer thickness and electrodes size, we present a new spectroelectrochemical NMR cell design consisting of nearly metal free symmetrically arranged large scale carbon fiber electrodes. Due to the advantages of modern NMR spectroscopy, a cell rotation is not necessary for high resolution measurements.

Rotating cell for in situ Raman spectroelectrochemical studies of photosensitive redox systems.

A recently developed rotating spectroelectrochemical cell for in situ Raman spectroscopic studies of photoreactive compounds without marked decomposition of the sample is presented. Photochemically and thermally sensitive redox systems are difficult to be studied under stationary conditions by in situ spectroelectrochemistry using laser excitation as in Raman spectroscopy. A rotating spectroelectrochemical cell can circumvent these difficulties.

Entrapped bonded hydrogen in a fullerene: the five-atom cluster Sc3CH in C80.

The synthesis and characterisation of the new endohedral cluster fullerene Sc(3)CH@C(80) is reported. The encapsulation of the first hydrocarbon cluster inside a fullerene was achieved by the arc burning method in a reactive CH(4) atmosphere. The extensive characterisation by mass spectrometry (MS), high- pressure liquid chromatography (HPLC), (45)Sc NMR, electron spin resonance (ESR), UV/Vis-NIR and Raman spectroscopy provided the experimental evidence for the caging of the five-atom Sc(3)CH cluster inside the C(80) cage isomer with icosahedral symmetry.